Natural Science Forum / Chemistry / Electrochemistry / August 2004

I've got 7.5V 2000mAh Ni-MH battery packs that I'd like to slow charge. I
only have fast chargers for them and don't see any slow chargers built for
them. I'm looking to build a slow charger for this application. Charging one
pack at a time is fine. Any help is really appreciated. ...

Can I use Ni MH battery packs instead of Nickel cadnium packs? Is it safe to do so, or if my phone came with a nickel cadnuim battery pack, am I stuck only using those types of batteries? I wanted to use
Ni MH instead because the charge would last longer and it doesn't have the ...

Hi, all,
I want to coat arount 200 nm Au on top of polymer substrate using
E-beam meathod. The possible polymer might be acrylic or Mylar. I
guess that there might be an adhesion layer between Au and polymer

I have a computerized telescope mount that needs a 12 volt source to
power two servo motors and an electronic control paddle.  Everything
works great when I use house current and a Pyramid 12 volt power
supply (which for some reason produces 13.8 volts.)

Can anyone tell me where I can find information about test procedures
for Li-ion batteries?
How do battery manufacturers know what the life expectancy of a
battery is?

Next time you're going on a trip where you need a portable heater, just bring
the 9.6V battery pack from your RC car and an AV cable! When the AV cable is
connected to the battery, it produces just about the right amount of heat for
any situation, such as a cold winter storm. I've ...

I've heard they can be up to 50wh/kg.  That is good.
But even say at 10wh/kg they discharge so fast (I think) that they may
be of use in hybrids.  You could have a very efficient ATkinson cycle
engine running and then use the capacitors at low rpm to give torque,

I'm designing a PC based Ni-CD/Ni-Mh/Li-Ion battery discharger and
charger. For the discharge function I would like to add a capacity
measurement feature that can tell me the cell capacity in mAh. For a
call rated 1000mAh for example, I would like to know if the cell

I got a stupid question, I've been buying really cheap powerplay brand
batteries because they're made by pure engergy corporation and due to the
battery markings under the label I have identified that they are the same
brand as pure engergy rechargables.

for powering a small model aircraft I'm intending to use some
LiPo cells with a relatively low capacity of 720 mAh, maybe only
350 mAh. Therefore I will of course need a LiPo-charger (such as
the Kokam LiPo 402) as well. As far as I've seen these LiPo-chargers

Arrhenius Equation suggest that the higher the temperature the faster a
given chemical reaction will be?
Is there any work on impedance changes over temperature?  And is there any
documented correlation between Arrhenius Equation and impedance changes.

What are the best type of batteries to use for flashlights and remote
controls (for TV, etc.)?
I don't know much about lithium batteries except they're supposed to be good
for high drain applications like digital cameras. Noone ever mentions how

Short circuit a NiCd battery, and throw it in gasoline.

Older UPS and modern low-end UPS takes about half a day to fully
charge a battery, but higher end UPS's are offering faster charge
time.  I took a measurement and they push as much as C/3 to C/2.5 .

Can you take a look at the following concerning double layer capacitance and let me know if you can think of any other factors that can effect it?
The value of the double layer capacitance depends on many variables including
1/  electrode potential
2/  temperature,